Oryou Sakamoto is the widow of Ryoma Sakamoto and serves as the chief overseeing the Mobile Shinsengumi's operations and members. She is the mother of Ryunosuke Sakamoto, a central figure frequently interacting with the Shinsengumi. Oryou is deeply concerned for her son's future, particularly when he expresses a desire to return to Shanghai, causing her significant emotional distress.

She exhibits tolerance regarding social and interspecies relationships. When questioned about accepting a potential half-monster daughter-in-law, her initial shocked reaction stemmed from an unrelated distraction; she later reveals she holds no objections to such a union.

In expanded media, specifically the 2007 pachinko game based on the series, Oryou appears in a stylized form. She is depicted in an inflated state during a bonus animation sequence, referencing a similar event from the anime's eleventh episode.